Copper alloy



United States Patent 3,421,888 COPPER ALLOY Matti J. Saarivirta,Marquette, Mich, assignor, by mesne assignments, to Calumet & HeclaCorporation, Evanston, 11]., a corporation of Delaware No Drawing. FiledAug. 12, 1966, Ser. No. 571,983 US. Cl. 75-159 3 Claims Int. Cl. C22c9/00 This invention relates to a copper base alloy having good responsesto precipitation hardening and cold workmg.

Copper alloys of high tensile strength, hardness and good electricalconductivity are well known in the art. Thus, alloys of this type arethe copper-beryllium alloys and particularly copper-beryllium-cobaltalloys. These, however, are expensive so that the cost limits their use.

One of the features of this invention is to provide a copper base alloyhaving good responses to precipitation hardening and cold working toproduce an alloy of high tensile strength, good electrical conductivityand excellent hardness that is considerably cheaper than previous alloyshaving these characteristics, the new alloy containing, by weight, about0.41.5% chromium, about 0.30.9% titanium, about 0.10.8% nickel, about0.020.l6% phosphorus, the remainder being substantially oxygen freecopper, in which the weight amount ratio of nickel to phosphorus isabout of nickel to 1 of phosphorus and the weight amount of titanium isabout 1-1.7 times the sum of the amounts of nickel plus phosphorus.

The copper of the alloy contains the lowest amount possible of oxygen.This can be either initially oxygen free copper which is ordinarilyproduced in a reducing atmosphere, an inert atmosphere or a vacuum or itcan be copper that has been deoxidized with such well known deoxidizersas phosphorus, silicon, lithium, calcium, calcium boride or the likewhich combine with the oxygen in the copper to eliminate itsubstantially completely.

The alloys of this invention have been found to be useful inmanufacturing resistance welding electrodes as well as electrical andelectronic components generally.

The presence of the chromium in the alloy increases the response of thealloy to precipitation hardening and gives increased hardness andtensile strength. The titanium also appears to increase the hardness ofthe alloy.

The new alloy may be fully annealed by solution heat treatment in anon-oxidizing atmosphere, either reducing or inert. This is a well knownprocedure in which the alloy is heated to a temperature between about9001000 C. and then cooled by rapid quenching. The solution heat treatedalloy of this invention responds excellently to precipitation or agehardening. This is generally done by reheating the quenched alloy forone hour or more at about 300-600 C. for the generally one or more hoursof aging. In general, the higher the temperature of heating the shorterthe aging time. In practice excellent precipitation hardening conditionshave been to reheat to about 500 C. for about 2 hours. Suchprecipitation hardening strengthens the alloy while at the same timeincreasing the thermal and electrical conductivity.

The strength and hardness of the alloy can be further increased by thecustomary cold working which is performed in the usual manner. This coldworking may be an intermediate step between the solution heat treatmentand the precipitation hardening or it may be done after precipitationhardening, as desired.

Thus the copper-chromium-titanium-nickelaphosphorus alloys of thisinvention are highly precipitation hardenable and give excellentresponse to cold working. Heat treatment at 500 C. after solutionannealing at 1020 C. results in an ultimate tensile strength of80,000-83,000 p.s.i., 77-83 Rockwell B hardness and 55-65% IACS RIGelectrical conductivity. When cold worked to a 15% reduction in area,the tensile strength is 90,000-97,000 p.s.i., hardness 88-92 and theelectrical conductivity is not changed. Very similar properties areobtained by solution annealing, 60% cold reduction and heat treating.The new alloys can be easily melted and cast without difficultyproviding the usual protective atmosphere is maintained.

The following tables set forth various alloys coming within theinvention, their treatments and their properties. In each example thecopper was melted first, then the chromium added and completelydissolved in the copper melt, then the titanium dissolved in the coppermelt and finally the nickel and phosphorus added and the entire moltenalloy mixed to a homogeneous condition. 500-1000 gram castings were thenmade at casting temperatures of 1110- 1200 C. in graphite and cast ironmolds with each 1000 gram casting being about 0.75 inch in diameter by12 inches long and the 500 gram castings being about 0.75 inch indiameter by 6 inches long. During the melting and the casting the meltswere maintained under non-oxidizing conditions in that they weresurrounded by an atmosphere of an inert gas, with argon being especiallypreferred for this purpose.

The following tables present various examples of alloys within theinvention and their characteristics. Thus, in the following Table No. 1there is shown the effect of various amounts of nickel and phosphorusforming nickelphosphide on the properties of basiccopper-chromiumtitanium alloys. The other tables record the effects ofvarious treatments on the alloys of this invention.

TABLE 1 Heat treated Elec. cond.,

VPN Rb percent IACS Solution annealed Hard- Elec.

ness cond., VPN percent IACS Percent Example Hardness Ni P Copper AlloyContaining 1% Chromium and 0.3% Titanium Copper Alloy Containing 1%Chromium and 0.4% Titanium Copper Alloy Containing 1% Chromium and 0.5%Titanium Copper Alloy Containing 1% Chromium and 0.9% Titanium TABLE 4Efiect of cold working after aging. Cast specimens hot forged to 0.45inch with 50% reduction, solution annealed at 1,020 C. for 30 minutes,

. 02 67 1' 1'0 81 24 04 74 1 35 21 guonched, aged at 500 C. for 2 hoursand cold worked various amounts 2 16 152 32 g 1n cross section] 08 16106 85 "0 1 99 19 145 81 0 Solution annealed Cold worked after aging 1%22 17 100 84 43 and aged 1 138 23 81 55 Alloy Hardness Elee. PercentHardness Elec. cond col cond.,

VPN Rb percent reduct. VPN Rb percent IAC 10 E 40 140 78 58 7 155 82 57X. TABLE 2 140 78 58 19 164 86 57 [Eilcct of heat treating temperatureson the hardness and electrical conductivity of the Cu-Cr-Ti-Ni-P alloys.The cast specimens were EL 29 134 2 9 164 82 61 solutioin tannealed tat1,020 011M232 minutes, quenched, and heat 134 75 19 155 86 61 t at i s me l t s s m e e p H 2: 1 E d Ex. 38 155 81 4o 9 172 no 49 condition m655 fi' fl Example 40C0pper alloy containing 1% chromium, 0.55%titanium,

VPN Rb 0.28% nickel and 0.032% phosphorus.

Example 2.Copper Alloy Containing 1% Chromium, 03% Titanium, 0.2% Nickeland 0.04% Phosphorus N0 aging 48 28 2O Aged at 450 C. 110 65 59 Aged at470 C 130 74 05 Aged at 500 C 145 70 00 Aged at 520 C. 126 09 00 Aged at550 C 117 64 72 Aged at 050 C 83 35 04 Aged at 700 C .1 03 (i0 TABLE 5Example 29.Coppe A1103: Containing 11% C hromiu1n, -7% Titanififiperltligssoiviiligssol lfigoilggiielzggdiggleltilndvieigldvgagfilNickel and 008% hobphorus annealed at 1,020 O. for 20 minutes, quenched,heat treated at 500 C. No aging 53 40 29 for 2 hours, and cold drawnafter heat treatment to 0.116 inch with Aged at sod 6.1: 148 81 a1 15%reducnm ma] 0 i gg g 30 Tensile Elong, Hardness Elce. g at 0 :1: 57 Ex.Condition strength, percent cond, d m C 74 23 p.s.1. 111 2 111. VPN Rbpercersrt 2. S01. annoaled. 38, 000 30 52 47 27 Aged 79, 000 10 141 6035 Cold drawn 82, 000 0 107 -00 00 I 0 S01. annealed... 43,000 30 51 4828 TABLE 3 Aged 82,000 13 145 78 e4 [Eilect of Serious solutlion all illtliillllg temperatures on tllietpropertiesl (at Gold 000 5 8790 63 theCu r-Ti-Ni-P a loys. 1e cast specimens were so u ion annea e at thetemperatures indicated for 30 minutes, quenched, and aged g -g gs 2, g;

0 at 500 for 2 1mm] 40 Cold drawn 231000 5 180 88-92 58 TemperatureHardness Elec. cond.,

' 128288. 21: 211 e a 2 a Cold drawn 92, 000 5 171 88-90 60 S-:33 2 900106 48 71 29. s01. annealed... 43, 000 23 53 58 25 p 88 106 Aged o 00013 150 so 58 $1111: 3 62 45 cold drawn es, 000 5 180 88-92 68 Example 20900 107 59 64 Example 38 e00 124 so 44 21 42, g; Example 2 925 no 57Cold drawn--." 901000 5 183 88-21 47 Example 8 025 61 Example 15 e25 10860 5e 2? g? Example 21 025 03 61 5O 5 180 884,2 55 Example 20 025 100 6365 I Emmple 43 Example ll-Copper alloy containing 1% chromium, 0.7%titanium, Example 2 50 114 G3 72 0.4% nickel and. 0.08% phosphorus.Example 8 950 118 60 08 Example 15. 950 117 05 65 Example 21... 950 12408 02 55 Example 29 950 124 07 65 Example 38 050 134 74 41 Example 2 975121 66 71 Example 8.- 057 124 71 60 Example 15. 075 124 09 61 Example21.-- 075 132 72 62 Example 29 075 72 e4 60 Example 38 975 144 77 40Example2 1 000 125 73 71 TABLE 6 Example 8: 1:000 134 73 65 The hardnessand electrical conductivity properties of the alloys cold Example 15.1,000 134 73 03 worked and aged after solution annealing. Cast specimenswere hot Example 21. 1, 000 134 74 62 forged 50%, solution annealed at1,020 0., cold worked various amounts Example 20. 1,000 132 2% 65 andthen aged at 500 C. for 2 hours] Exam e38 1 000 14 p Percent Cold workedcondition Cold worked and aged Example 2 1, 020 70 69 cold re- Example 81,020 145 78 66 Example duct. in Hardness Eleg. Hardness Eleg. Exam le1.). 1 020 140 77 64 cross con con mangle 21. 11020 151 so 62 sect. VPNRb percent VPN Rb percent Example 29 1,020 148 82 01 IACS 1 Example 381,020 100 84 43 70 40 16 78 44 25 80 58 Example 2 1,040 143 7e 70 34 10658 24 190 83 80 Example 8 1, 040 140 79 06 40 110 61 24 140 85 61Example 15. 1, 040 142 77 04 Example 21- r 1,040 147 82 03 38 10 80 5118 88 55 Example 20- 1, 040 146 80 00 34 112 05 20 173 80 55 Example 381, 040 143 79 44 75 46 120 66 19 181 91 55 TABLE 7 [Efiect of heattreating temperatures on the properties 01 the cold drawn wires ofCu-Cr-Ti-Ni-P alloys. The 0.128 inch diameter wires were solutionannealed at 1,020 C. for 20 minutes, quenched, cold drawn to 0.081 inchwith 60% reduction in area and heat treated at various temperatures'for1 hours] Tensile Elong., Hardness Elec. Example Condition strength,percent VPN cond.,

, p.s.i. in 2 percent inches IACS 2 C'old drawn- 64,000 3 124 26 Agedat:

9 1. Cold drawn 64,000 3 124 26 Aged at:

350 O 66,000 3 120 32 400 C ,000 6 138 41 450 C 83, 000 8 170 56 475 C000 8 171 61 500 C 90, 000 9 169 65 525 C"... 85,000 9 165 67 550 C ,0008 153 67 Cold drawn... 67,000 3 128 23 Aged at:

29 Cold drawn". 66,000 3 124 26 Aged at:

350 C 65,000 4 120 29 400 C- 000 8 138 39 450 C..." 85, 000 10 163 54475 C... 000 10 174 60 500 0..." 90,000 10 169 63 550 C.. 74, 000 8 15365 38 Cold drawn 67,000 3 126 Aged at:

350 000 4 133 24 400 O 70, 000 7 143 450 C... 91, 000 10 177 39 47594,000 8 182 44 500 C 92, 000 9 180 47 550 C.... 92, 000 8 170 51Tensile Elong., Hardness Elecl Example Condition strength, percent VPNcond.,

p.s.i. in 2 percent inches IACS 41 Cold drawn 69,000 123 22 Aged at: 3500..... 70,000 4 134 26 400 C 74, 000 7 143 33 450 C-.-.- 88, 000 10 17743 475 C 91-, 000 0 177 47 500 0---. 91, 000 9 174 52 550 C-.- 89, 00011 165 53 00 0..... 73, 000 9 140 Having described my invention asrelated to the embodiments set out herein, -'1 is my intention that -theinvention be not limited by any of the details of description, unlessotherwise specified, but rather be construed broadly within its spiritand scope as set out in the accompanying claims.

I claim:

1. A copper base alloy having good responses to precipitationhardeningand cold working consisting essentially of: about 0.41.5% chromium,about ;0.30.9% titanium, about 0.10.8% nickel, about 0.020.16%phosphorus, and substantially. the entire remainder-a member of theclass consisting of initially oxygen free and deoxidized copper, theamount ratio of nickel to phosphorus being about 5 of nickel to l ofphosphorus and the amount of titanium being about 11.7 times the sum ofthe amounts of nickel plus phosphorus, the percentages and amounts beingby weight.

2. The alloy of claim 1 precipitation hardened and cold Worked toproduce in the alloy high tensile strength, good electrical conductivityand excellent hardness.

3. The alloy of claim '1 in which the amount of chromium is about 1%.

References Cited UNITED STATES PATENTS I 1,991,162 2/1935 Kroll 148-32.5X 2,189,198 2/ 1940 Qomstock -164 X 2,362,007 11/1944 Hensel et al.75--153 X 2,783,143 2/1957 Johnson et al 75164 X 3,162,529 12/1964 Doi75-164 X FOREIGN PATENTS 120,469 10/1945 Australia.

CHARLES N. LOVELL, Primary Examiner.

U.S-. Cl. X.R. 75-153, 164

1. A COOPER BASE ALLOY HAVING GOOD RESPONSES TO PRECIPITATION HARDENINGAND COLD WORKING CONSISTING ESSENTIALLY OF: ABOUT 0.4-1.5% CHROMIUM,ABOUT 0.3-0.9% TITANIUM, ABOUT 0.1-0.8% NICKEL, ABOUT 0.02-0.16%PHOSPHORUS, AND SUBSTANTIALLY THE ENTIRE REMAINDER A MEMBER OF THE CLASSCONSISTING OF INITIALLY OXYGEN FREE AND DEOXIDIZED COPPER, THE AMOUNTRATIO OF NICKEL TO PHOSPHORUS BEING ABOUT 5 OF NICKEL TO 1 OF PHOSPHORUSAND THE AMOUNT OF TITANIUM BEING ABOUT 1-1.7 TIMES THE SUM OF THEAMOUNTS OF NICKEL PLUS PHOSPHORUS, THE PERCENTAGES AND AMOUNTS BEING BYWEIGHT.